Same thing on a 2009 8-core 2.93Ghz Xserve. I have reinstalled everything. Twice. The VMs (One OS X EL Cap and one WinServer 2012) work fine with remote access and all servers on them work fine. Going to the host OS, though, Fusion is hung up. If I can activate any other app the machine is running fine. Fusion just shows beachballs. Sucky beachballs. OS X ElCap. Fusion 8.5.3. 64GB RAM. 240 GB PCI SSD startup drive. Everything else runs great on it. Fusion, not so much. Grrrr.